The 8660A mainframe uses thumbwheel switches to select CW output frequencies. Frequencies up to 1300 MHz can be enetered directly with 1 Hz resolution.
Frequency Accuracy and stability: CW frequency accuracy and long term stability are determined by reference oescillator in 8660C mainframe or by an external reference if used.
Internal: 10 Mhz quartz oscillator.
External: rear panel switch allows operation from 5 MHz or 10 Mhz frequency standard at a level between 0.2V and 2.0V rms into 170 Ohms.
Reference Output: rear panel BNC connector provides output of reference signal selected at level of at least 0.5V rms into 170 Ohms.
Option 100 - 11661B Frequency Extension Module